1. Field of the Invention
The present invention relates to an optical fiber adapter, and more particularly, to an optical fiber adapter with a shutter member.
2. Description of the Related Art
Recently, the optical fiber has been widely used as signal transmission media because of its high bandwidth and low loss nature. In order to transmit over a longer distance without the need of repeaters, it is common to use a high power diode laser to launch a laser beam into the optical fiber. However, the high power laser beam used to carry information is usually invisible. In other words, the human eyes will be unable to sense the high power laser beam if it leaves from the open end of a fiber cable. Thus, it is required to obstruct the high power laser beam to avoid hurting the eyes when the laser beam leaves from an optical fiber.
Referring to FIG. 1, a conventional fiber adapter 100 includes a housing 110 having a plurality of side walls 160. The side walls 160 define a receiving recess 120. One of the side walls 160 is provided with a slot 130 for mating with the key 192 of the connector 190 when the connector 190 is inserted into the receiving recess 120. In addition, the outer surfaces of two opposite side walls 160 are provided with recesses 140 that a clip (not shown in the figure) can be disposed thereon to facilitate the adapter 100 to be mounted on a panel.
When the adapter 100 is used to couple two connectors 190 together, the two connectors 190 are respectively inserted into the receiving recesses 120. The ferrules 196 of the connectors 190 thus slide into a hollow sleeve (not shown in the figure) and are brought into axial alignment and contact with each other. A light beam will be able to propagate from the fiber cable 194 of a connector 190 through the interface between the two ferrules 196 and then reach the fiber cable 194 of the other connector 190, and vice versa.
When one connector 190 is disconnected from the adapter 100, the light beam originally propagating from the connector 190 still kept in the adapter 100 to the presently disconnected connector 190 will now leave the ferrule 196 and emit from the receiving recess 120. If the emitted light beam is high power and not obstructed, a lasting exposure to such light beam is harmful to people, particularly to the eyes. Thus, to avoid exposing to the high-power light beam, it is common to use a cap 180 to block up the unused receiving recess 120. This can obstruct the light beam and also prevent the receiving recess 120 from dust. If a connector 190 would like to be mated with the adapter 100, the cap 180 is required to be removed. However, the cap 180 is apt to get lost and it is still possible to expose the eyes to the light beam during mating.
Referring to FIG. 2, a conventional fiber adapter 200 is generally the same as the adapter 100 but further includes a cover 250 pivotally connected to the housing 110. The cover 250 covers the receiving recess 120 in its closed position. A spring 260 can force the cover 250 to be pivoted to its closed position when the receiving recess 120 is not mated with a connector 190. Thus, the cover 250 is capable of obstructing the light beam emitted from the receiving recess 120 in its closed position. If a user would like to mate a connector 190 with the adapter 200, he is first required to lift the cover 250 from its closed position and then to insert the connector 190 into the receiving recess 120. Upon pulling out the connector 190, the cover 250 is pivoted to cover the receiving recess 120 through the spring 260. As a result, the user has no chance to expose to the high-power light beam. However, the construction of the adapter 200 is much more complex than that of the adapter 100.
Referring to FIG. 3, a conventional protection cap 300 for the fiber adapter 100 includes a hollow housing 310 with two opposing openings and a cover 350 pivotally connected to the housing 310. The cover 350 is pivoted to cover one of the two openings through a spring 360. The protection cap 300 can be put on the adapter 100 and cover the outer surfaces of the side walls 160 and the receiving recess 120 of the adapter 100. When a user would like to mate a connector 190 with the adapter 200, he is required to lift the cover 350 from its closed position and then to insert the connector 190 into the receiving recess 120. Likewise, upon pulling out the connector 190, the cover 350 is pivoted to cover the receiving recess 120 by the spring 360. As a result, the user has no chance to expose to the high-power light beam emitted from the receiving recess 120. However, the structure of the protection cap 300 is somewhat complex and therefore it is not inexpensive. The introduction of the protection cap 300 to obstruct the light beam will cost much.
Referring to FIG. 4, it illustrates a conventional shutter member 400 for the optical fiber adapter 100. The shutter member 400 includes a clamping portion 410. The one end of the clamping portion 410 has a clamping indentation 412 for attaching to one of the side walls 160 of the adapter 100 and the other opposite end of the clamping portion 410 has at least one hook 414. In addition, the shutter member 400 further includes a curved elastic shutter plate 420 extending from the clamping portion 410.
Referring to FIGS. 5 and 6, when the shutter member 400 is used in the adapter 100, the shutter plate 420 extends into the receiving recess 120 to obstruct the light beam 610 emitted therefrom. As a result, the occurrence of exposure to the harmful light beam 610 can be avoided. In addition, there is no need to detach the shutter member 400 from the adapter 100 prior to inserting the connector 190 into the receiving recess 120. When the connector 190 is inserted into the receiving recess 120, it will push down the elastic shutter plate 420 to the gap between the connector 190 and the side wall 160. Upon pulling out the connector 190, the elastic shutter plate 420 will quickly return to its original position to obstruct the light beam 610 as a result of elasticity.
However, when the shutter plate 420 is pushed down by the connector 190, it will experience a large deflection. Therefore, the shutter plate 420 is prone to undergo a plastic deformation.
Accordingly, there exists a need to provide an optical fiber adapter to solve the aforesaid problems.